X-ray radiographic expansion measurements of isochorically heated thin wire targets

Solid density matter at temperatures ranging from 150 eV to $<5 eV$ has been created by irradiating thin wire targets with high-energy laser pulses at intensities $≈1018W/cm2$⁠. Energy deposition and transport of the laser-produced fast electrons are inferred from spatially resolved K_α-spectroscopy. Time resolved x-ray radiography is employed to image the target mass density up to solid density and proves isochoric heating. The subsequent hydrodynamic evolution of the target is observed for up to 3 ns and is compared to radiation-hydrodynamic simulations. At distances of several hundred micrometers from the laser interaction region, where temperatures of 5–20 eV and small temperature gradients are found, the hydrodynamic evolution of the wire is a near axially symmetric isentropic expansion, and good agreement between simulations and radiography data confirms heating of the wire over hundreds of micrometers.